Improvement in the manufacture of wash-boilers and other vessels



q UNITED -:STATEs I PATENT Ornicn.

G. H. HAZELTON, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN THE MANUFACTURE OF WASH-BOILERS AND OTHER VESSELS.

Specification forming part of Letters Patent No. 44,369, dated September 20, 1854.

v To all whom it may concern.-

Be it known that I, G. H. HAZELTON, of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented a new and useful Improvement in .the Manufacture of Wash-Boilers and other Vessels Made of Tinned Iron; and Ihereby declare that the following is a full and exact description of the same.

In the manufacture of wash-boilers previous to my invention it had been difficult to obtain a durable and incorrodible bottom. The bottoms of such boilers have commonly been made either of tinned sheet-iron (tin-platc) or of sheetcopper. Tinned iron isobjectionable for the reason that the tinbecomes corroded, it being easily acted on by both acids and alkalies.

There is also another objection to the use of tin-plate bottoms. They are usually pressed between dies, so as to make the bottoms of boilers fit upon the top openings of stoves and ranges. By this operation of pressing or stamping the surface-coating of tin is drawn and sometimes abraded, and the sheet-iron itself is strained, so that the corrosive action of soap and hot water on the inside and of the fire on the outside soon reaches the iron, and the bottom is destroyed or rendered useless. To avoid these objections to the use of tinplate it has been common to substitute a bottom of sheet-copper having the body of the boiler of tin-plate; but copper is objectionable, both on account of its great cost and on account of the difficulty of keeping a sound solder-joint between the copper bottom and the tin plate body of the boiler, for it is well known that when two such opposite metals as copper and tin or copper and iron are brought together local galvanic action is easily established, which soon corrodes the tin or iron. This corrosive action once started soon destroys the joint between a copper bottom and the body of the boiler. It is also well known that copper and iron expand unequally under the influence of heat, copper expanding more than iron. This unequal expansion makes it difficult to keep the solder-joint between the bottom and sides of the boiler or kettle from being torn open, and thus causing the vessel to leak.

After long-continued experiments I have overcome the objections above mentioned and have succeeded in producing a bottom for wash-boilers and other similar vessels made of tinned iron, which is durable and which may be produced much more cheaply than a copper bottom. This improved bottom for washboilers and other like vessels, made as hereinafter described, constitutes my invention.

To enable others skilled in the art to make, and use my invention, I proceed to describe the process which I prefer to use in manufacturing it.

I take tin-platesuch as is commonly used for manufacturing wash-boilers-and press it in a die or dies in the manner usual in making stamped ware from tin-plate. After the sheet of metal has been pressed, stamped, or treated in any other way, so as to bring it to the proper or desired shape for the bottom of a wash-boiler or like vessel, Icoat it with a compound metal or alloy of lead, tin, and antimony, or when hardness is not required of lead and tin. The coating I perform by dipping in a bath of the alloy in the manner usual in making tinned iron. This coating completely fills any cracks that may exist in the surface of the plate, either from imperfect plating or which may have been produced in the process of stamping or pressing. The coating with alloy also adds much to the strength of the bottom and protects it against the corrosive action of acids, alkali'es, &c. For the alloy of lead, tin, and antimony, very good proportions are fifty-eight parts of lead, (tea-lead is preferred,) thirty-seven parts of block-tin,

and five parts of antimony; or, when antimony is omitted, fifty-eight parts of lead and fortytwo parts of tin. I do not, however, limit myself to these proportions, since others will answer, and it is well known that a great variety of useful alloys of lead, tin, and antimony have been prepared. The mode of preparing them, and their character as to hardness, corrodibility, and the manner of coating sheet metal with them, are known to persons skilled in the art of making and working tin-plate, and

therefore need not be described.

I do notconfine myself to the exact order of operations above stated in making bottoms for boilers and other vessels, since substantially the same article may be produced by varying the order of the several operations. Thus, for example, the sheet-iron may be stamped, then tinned, and afterward coated with the protecting alloy; but the mode first Wa sh-boilers and other similar vesse1s,\made ofthe material and substantially as herein set forth and described.

G. H. HAZELTON Witnesses:

J OHN S. HoLLrNesHEAn, J our: D. BLooR. I 

